Electrical connections



Oct. 3l,l 1967 J. E. MARLEY T AL 9 ELECTRICAL CONNECTIONS Filed April23, 1964 2 Sheets-Sheet 1 United States Patent 3,350,679 ELECTRICALCONNECTIONS James Earl Marley, Middletown, and Thomas Parkison Warne,Jr., Camp Hill, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Apr. 23, 1964, Ser. No. 362,057 7 Claims. (Cl. 339-223) Thisinvention relates to the formation of electrical connections betweenterminal posts and conductors.

An object of the invention is to provide an improved form of terminalpost. A further object is to provide a terminal post to which aplurality of wires can be electrically connected in a short length ofthe post. A still further object is to provide a terminal post which canbe effectively preinsulated with case. A still further object is toprovide a method and apparatus for forming electrical connections withhollow terminal posts which have an axial seam extending along one sidethereof.

These and other objects of the invention are achieved in a preferredembodiment thereof comprising a generally channel-shaped elongatedterminal post having a web portion and having sidewalls extending fromtwo opposite sides from the web. The sidewalls are reversely curledtowards each other and towards the internal surface of the web. Theelectrical connection is made by means of a connecting member which isadapted to be telescopically moved into the post and between the edgesof the curled sidewalls and the internal surface of the Web of the post.In accordance with a preferred embodiment, the connecting member isguided into the post by means of a mandrel having a groove thereinconforming to the cross-section of the connecting member and having anopening extending therethrough and intersecting the groove. In use, theend portion of a wire is inserted into the opening and the connectingmember is moved through the groove in the mandrel, against theconductor, and into the terminal post. During this movement of theconnecting member, it drags the end portion of a conductor from theopening in the mandrel, over the surface of the groove in the mandrel,and into the terminal post. In the finished electrical connection then,the conductor is clamped by the connecting member against the internalsurface of the web portion of the post and emerges from confinedrelationship at the end of the connecting member which is proximate tothe base of the post. The conductor extends externally through the openaxial scam in the post to further portions of the electrical circuit.

In the drawing:

FIGURE 1 is a perspective view of a terminal post having a pair ofconductors electrically connected thereto in accordance with theinvention;

FIGURE 2 is an exploded view showing the terminal post and theconnecting member;

FIGURE 3 is a perspective view showing the mandrel and connecting memberpushing means in alignment with a connecting member and with the mandreldisposed against the upper endof a terminal post;

FIGURE 4 is a sectional side view showing the positions of the mandrel,the connecting member, and the post at the time the connecting membermoves against the conductor and during initial severing of theinsulation on the end portion of the conductor; and

FIGURE 5 is a view taken along the lines 55 of FIG- URE 1.

The present invention incorporates some general principles described andclaimed in the copending application of Robert F. Cobaugh, Ser. No.171,074, filed Feb. 5, 1962, for Electrical Connections to whichreference is hereby made.

An electrical connection in accordance with the present inventioncomprises a generally channel-shaped post 2 which in the disclosedembodiment extends from a panel board 4. The post 2 has a Web 6 fromwhich sidewalls 8 extend, these sidewalls being curled inwardly towardseach other and towards the internal surface of the web as shown in 10 sothat the edges 12 of the sidewalls are opposed to the internal surfaceof the web. Advant-ageously the corners of the sidewalls at the upperend of the post are beveled as shown at 14 to facilitate movement of aconnecting member 18 into the post as will be described below. The web 6is provided with an outwardly concave axially extending rib 16 whichforms a pocket on its internal surface for reception of the conductorcore of a wire as shown best in FIGURE 5. The sidewalls of the post arepreferably cut away intermediate the ends of the post as shown at 9 forreasons explained below. The disclosed form of post is provided withtabs 11 on its lower end by means of which it is secured to the board 4.Alternatively, the post may be provided with an integral disengageableconnecting means on its lower end, for example a contact of the typeused for printed circuit board.

The connecting member 13 which holds the end portion of a conductoragainst the internal surface of the web 6 of the post is a generallyrectangular flat plate-like member having the corners of its leading endbeveled as shown at 20. The disclosed type of connecting member hasoutwardly struck cars 22 adjacent its leading end to function as aninsulation support for holding the end portion of the insulation of thewire 26. The upper end of the connecting member 18 has a tab 28extending on the same side thereof as the ears 22 for facilitatingremoval from within the terminal post, the width of this tab being lessthan the distance between the opposed curled surfaces 14 of thesidewalls 8 of the post.

The electrical connections shown at FIGURE 1 are advantageously formedby means of a mandrel 30 and a connecting member pushing device 44.Mandrel 30 has an axially extending groove 32, the width of which isslightly greater than the width of the connecting member 18 so that theconnecting member can be pushed downwardly from the position shown inFIGURE 2 through the groove and into the terminal post. The sidewalls 34of the mandrel on each side of the groove 32 overhang the floor of thegroove so that the connecting member is captured during its movementinto the post and accurately guided along its path of movement. Anopening 38 extends through the mandrel 30 on an axis which intersectsthe longitudinal axis of the groove 32, the diameter of this openingadvantageously being slightly greater than the diameter of theinsulation of the wire 26. The edges 40 of this opening are relativelysharp in the embodiment shown for the reason that these edges areutilized to cut into the insulation during relative downward movement ofthe connecting member 18 into the mandrel. A shallow channel 42 isprovided on the floor of the groove 32 extending from the opening 38 tothe lower end of the mandrel for the purpose of guiding the conductingcore of the wire during downward movement of the connecting member. Theclip pusher 44 has a leading end conforming to the trailing end of theconnecting member 18 and is reciprocable along a path extending throughthe groove 32 of the mandrel. It will be understood that the connectingmember pushing device 44 and the mandrel may be incorporated into asuitable hand-tool or automatic wiring machine of the general type shownin the above-identified Cobaugh application, Ser. No. 171,074.

In use, the mandrel 30 is positioned against the upper end of theterminal post with the floor of the groove 32 in substantial alignmentwith the internal surface of the web 6 of the post. The wire is insertedinto the opening 38 and the connecting member pusher 44 is actuated topush the connecting member downwardly, against the transverselyextending wire 26, and into the terminal post. Upon engagement of theconnecting member with the wire, the wire is forced against the edges 40on each side of the channel 42 and compressed so that upon furtherdownward movement of the connecting member, extremely high stresses areestablished in the insulating sheath of the wire. The wire iscircumferentially severed as a result of these stresses and theconducting core 28 of the wire at the end portion thereof is draggedfrom the opening 38 while severed section of insulation 26 remains inthe opening, see FIGURE 4. Upon further downward movement of theconnecting member the exposed strands at the end of a Wire are draggeddownwardly over the surface of the mandrel and over the internal surfaceof the web 6 of the post until the connecting member comes to rest. Inthe finished connection then, the stripped end of the wire is clampedbetween the internal surface of the web 6 with the wire emerging frombeneath the connecting member 18 at the end thereof which is proximateto the base of the post. It will be apparent that the end portion of theinsulation of the wire 26 will be trapped within the ears 22 of theconnecting member and that the wire will emerge through the open seam ofthe post.

It is advantageous to provide the gaps 9 in the sidewalls of the postfor the purpose of separating the clamping stresses imposed on the twoconductors shown in FIGURE 1 and preventing adverse effects which mightotherwise take place. For example, in FIGURE 1, the upper conductor isclamped against the post by the sidewall portions which lie above thegaps 9 while the lower conductor is clamped by the lower sidewallportions. If either conductor is slightly oversized, the clampingpressure imposed on the other conductor will not be reduced.

The post and the connecting member can have configurations other thanthat shown so long as the post has an open seam on one side and theconnecting member is adapted to be telescoped into the post. Onepossible modification of the mandrel is that the opening 38 can beeliminated and the wire merely positioned across the top of the mandrelduring use.

It will be apparent that many of the general principles and many of themodifications applicable to the aboveidentified Cobaugh invention, Ser.No. 171,074, are likewise applicable to the present invention. Forexample, the insulation of the wire can be slit by means of a knife edgein the mandrel in accordance with the general principles of applicationSer. No. 282,092, filed May 21, 1963, by Robert F. Cobaugh. Theprinciples of the present invention can be applied where the wire isprovided with a thin coating of film-type insulation such as polyvinylformal resin. Where a film insulated wire is involved, the flattening ofthe wire which takes place during its movement over the surface of themandrel results in the exposure of fresh metal surface and breaking ofthe film insulation so that an electrical connection will be establishedbetween the portion of the wire held by the connecting member and theinternal suface of the web 6 of the terminal post.

An advantage of the invention is that the connecting member, whichconstitutes the loose piece portion of the connection, may comprise asimple fiat plate which is extremely durable and rugged. A furtheradvantage is that the irregular shape of the post permits the attainmentof a relatively stiff post for a given thickness of metal which is noteasily bent or damaged. Preinsulation of the post is accomplished withrelative case since it is only necessary to provide an insulating filmon the external surface of the post, this external surface beingrelatively smooth and gently curled and, therefore, amenable to theprovision of a film-type insulating material. The connecting member neednot be insulated since it is confined within the post in the finishedelectrical connection.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is otlered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

We claim:

1. An electrical connection comprising a terminal post, a conductor, anda connecting member, said post being in embracing relationship to saidconnecting member and having an open seam extending axially along oneside thereof, said conductor being contained between said post and saidconnecting member and emerging from confined relationship through saidseam.

2. A connection as set forth in claim 1 wherein said post is ofgenerally channel-shaped cross-section comprising a web and sidewalls oneach side of said web, said sidewalls having marginal portions curledtowards each other and towards said web, said connecting member beingdisposed against said web and being held against said web by said curledsidewall portions.

3. An electrical connection comprising a terminal post, a conductor anda connecting member, said post being hollow and having an axiallyextending open seam on one side thereof, said connecting member beingtelescoped into said post, said conductor being confined between aninternal surface of said post and the opposed surface of said connectingmember, said conductor extending towards the base of said post andemerging through said open seam.

4. An electrical connection as set forth in claim 3 wherein said post isof generally channel-shaped crosssection comprising a web and sidewalls,said sidewalls being curled towards each other and towards said web,said connecting member being clamped against the internal surface ofsaid web by said sidewalls.

5. An electrical connection as set forth in claim 4 wherein saidconductor is an insulated wire, the portion of said wire confinedbetween said post and said connecting member being stripped, saidconnecting member having an outwardly cupped insulation support on theend thereof which is adjacent to the base of said post, the end portionsof insulation of said wire being contained within said insulationsupport.

6. Means for making an electrical connection comprising a hollow postmember having an axially extending open seam and a connecting membertelescopically movable into said post, said connecting member beingaxially movable, with respect to said post, past a transverselyextending conductor and into said post whereby said connecting memberdrags said conductor into said post, and a section of said conductor isconfined between an interior surface of said post and the opposedsurface of said connecting member with said conductor emerging fromconfined relationship through said open seam and between said connectingmember and the base of said post.

7. Means for making an electrical connection as set forth in claim 6wherein said post is of generally channelshaped cross-section, said posthaving a web and sidewalls on two opposite sides of said web, saidsidewalls being curled towards each other and towards said web, saidconnecting member comprising a plate dimensioned to be telescopicallyslid between edge portions of said sidewalls and the internal surface ofsaid web.

References Cited UNITED STATES PATENTS 3,021,503 2/1962 Hopkins et a1.339-223 X 3,128,143 4/1964 Stizler 339-223 3,191,281 6/1965 Cobaugh339-97 X 6 Blanchenot 339223 X Cobaugh 29155.55 Cobaugh 339-97 Hammell339-97 MARVIN A. CHAMPION, Primary Examiner.

PATRICK A. CLIFFORD, W. DONALD MILLER,

EDWARD C. ALLEN, Examiners.

1. AN ELECTRICAL CONNECTION COMPRISING A TERMINAL POST, A CONDUCTOR, ANDA CONNECTING MEMBER, SAID POST BEING IN EMBRACING RELATIONSHIP TO SAIDCONNECTING MEMBER AND HAVING AN OPEN SEAM EXTENDING AXIALLY ALONG ONESIDE THEREOF, SAID CONDUCTOR BEING CONTAINED BETWEEN